Henry hoffmann



UNITED STATES PATENT OFFICE.

HENRY HOFFMANN, OF NEXV YORK, N. Y.

AUTOMATIC FAN.

Specification of Letters Patent No. 24,638, dated July 5, 1859.

To all whom t may concern;

Be it known that I, HENRY HOFFMANN, of the city, county, and State of New York, have invented a new and Improved Fan; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specilication, in which- Figure l, is a front elevation of my invention, and Fig. 2, is a side elevation of ditto.

Similar letters of reference in the two views referto corresponding parts.

The object of this invention is to arrange the fan in such a manner that it can 4easily be operated by a clock work or that a number of them can be operated by a steam engine or by some other motive power with a trifling expenditure of power; and this invention consists in arranging the wings of the fan on a fan carrier which is suspended from a rock shaft by means of two cords or belts which are secured to the extreme ends of two arms and which wind in opposite directions on rollers, so that by tipping the rock shaft alternately to one side and to the other, the gravity of the fan-carrier assisted by the weight of the fan itself causes the latter to assume a swinging motion, no more power being required but just enough to tip the rock shaft from one side to the other.

To enable those skilled in the art to fully understand and use my invention, I will proceed to describe its construction and operation.

A, represents a base or platform to which a vertical standard B, is rigidly attached. F irmly secured to the upper end of this .standard is a horizontal arm O, and suspended from this arm by means of loops a, and hooks is the rock shaft D. One of the hooks 7J, is extended through the standard B, forming a pin b to which a rod E, is secured by means of a set screw o. This rod serves to impart motion to the rock shaft D.

Each end of the rock shaft D, is provided with two arms F, F, extending on opposite sides of and at right angles to the rock shaft, as clearly represented in Fig. l. Belts or cords f, f', are secured to the extreme ends of the arms F, F', and these belts wind on rollers G, in opposite directions, each of the rollers being provided with two grooves so that the belts dont interfere with each other.

Instead of round belts or cords, flat bands might be used and in this case it would not be necessary to groove the rollers G, but the arms as well as the faces of the rollers would have to be wider, in order to give the required room for the bands. The ends of the belts 7, f', are secured to the rollers by means of holes CZ, made through the rollers near to their circumference, and they (the belts) wind round pins c, on the top edge of the arms F, F, so that by turning these pins the ropes can be made tighter or slacker at pleasure.

The rollers Gr, are united by the fan-carrier H, to the central part of which the two fans or wings I, are rigidly attached. A small tube g, passes through the central part of the fan-carrier which is partly filled with shot or mercury, whereby the momentum of the wings is increased when the same are in motion.

The operation is as follows When the arms F, F are in a horizontal position, the fan-carrier, independent from its attachments, will place itself in the center of the arms and the strain on both the belts f, f, will be equal. As soon as this is the case, the apparatus is in equilibrium and no motion takes place. But when the arms are brought in an inclined position, the strain on that belt, the end of which has been elevated with the arm to which it is attached, will exceed the strain on the other belt, and a rotary motion will be imparted to the fan carrier, until it is placed in such a position as represented in Fig. l, where the strain on both belts is again at equilibrium. If from this position the arm F', is raised until the inclination of the arms is in the other direction, the strain on the belt f', will become larger than the strain on the belt f, and the fan carrier will be rotated in the direction of the arrow, marked upon it, carrying with it the wings or fans, the momentum of which is increased by the shot or mercury in the tube g, so that by the motion of the wings a powerful but agreeable draft is created, and the fan-carrier will not cease to rotate until it arrives at the outer end of the arm F, assuming a position exactly opposite to the one represented in Fig. l. By alternately inclining the arms F, F', from one side to the other the fan carrier will assume a reciprocating rolling motion whereby the fans are kept in motion What I do claim as new and desire to se'- cure by Letters Patent, is-

The arrangement of the rock shaft D, arms F, F', belts f, f', and rollers Gr, or their equivalents, to operate in combination with the fan carrier H, substantially as and for the purpose specified.

HENRY HOFFMANN.

parts as representedin the drawings- .but J. W. CooMs, having thus fully described my invention, R. S. SPENCER. 

